Rotator muscles are a group of muscles in our bodies that help us move and rotate different body parts, like our arms and legs. They allow us to perform actions like lifting, twisting, and turning. Full definition
Sciatic pain, or sciatica, is most commonly caused by compression or irritation of the sciatic nerve that runs from each side of the lower lumbar and lumbosacral spine through the buttock and all the way down to the foot and in most cases, it's the piriformis muscle (a small hip rotator muscle located in the buttock region) that irritates the nearby sciatic nerve, thereby causing pain and numbness. (fitnessandpower.com)
Strengthening exercises concentrate more specifically on the external rotator muscles (the ones that rotate the arm out) and the scapular stabilizers (muscles that support the shoulder blade). (sportsinjuryclinic.net)
The shoulder rotator muscles lie beneath the large deltoid muscles and allow the arms to rotate into various positions. (bodybuilding-wizard.com)